The prior art, as exemplified by U.S. Pat. No. 2,873,794, issued to J. D. Leslie et al on Feb. 17, 1959 for an "INERTIA LATCH" and U.S. Pat. No. 3,549,202 issued Dec. 22, 1970 to John A. Boschen and Albert R. Close, for "SEAT BACK INERTIA LATCH", disclosed the use of inertia latch mechanisms for holding the pivoted or folding seat backrest of certain motor vehicle seat assemblies, such as those utilized in two-door models, against tiltable movement relative to the horizontal seat cushion. In such inertia latch mechanisms, the latch pawl or the like normally is positioned in a latching attitude. The inertia of the latch pawl is utilized to prevent forward tilting movement of the backrest when the deceleration rate of the vehicle exceeds a predetermined maximum, such as occurs in an accident or under "panic stop" conditions. The latching of the backrest under such conditions contributes to the stability of the seat occupant and also enables the backrest to function as a protective barrier for the rear seat occupants.
When a moderate force is applied to the backrest to tilt it forwardly, the latch pawl is moveable either by gravity or spring bias to a non-latching attitude. The backrest thus may be tilted forwardly by the application of moderate manual pressure at a low rate such as is desireable to permit ingress or egress to or from the rear seat area of the passenger compartment.
It is an object of the present invention to provide a latch pawl that is normally biased, as by gravity, into engagement with a cam means operative to control the latching attitude of the latch pawl relative to a detent, the co-action between the latch pawl and the cam means causing a positive pre-positioning of the latch pawl into latching attitude and a better controlled movement of the latch pawl into and out of latching attitude than is obtainable by known inertia latch mechanisms.